Switching apparatus and controlling method thereof

1. A switching apparatus comprising: a DC voltage output unit to output a DC voltage; a switching element supplying the DC voltage to a load; a power detection unit detecting power supplied from the switching element to the load; a driver configured to control the switching element in a manner of PWM according to an output from the power detection unit; and a stop unit configured to stop the PWM control if a value of the DC voltage is lower than a first threshold value, wherein the first threshold value is lower than a minimum operation voltage value of the power detection unit wherein the apparatus has a second threshold value higher than the minimum operation voltage value of the power detection unit, and if the value of the DC voltage is lower than the second threshold value, the driver controls the switching element at a constant duty ratio.

2. The switching apparatus as set forth in claim 1 , wherein the driver periodically holds and resets a duty ratio for controlling the switching element in the PWM manner, and if the value of the DC voltage is lower than the second threshold value, the driver controls the switching element at a duty ratio held in the drive unit.

3. The switching apparatus as set forth in claim 1 , wherein the load is a solenoid that provides a predetermined displacement according to a supplied current.

4. The switching apparatus as set forth in claim 3 , wherein the power detection unit detects the current supplied to the load.

5. The switching apparatus as set forth in claim 1 , wherein the DC voltage output unit is a battery.